Control device for mechanical refrigeration machines



Nov. 1, 1932.

CONTROL DEVICE FOR HECHA Filed July 3, 1929 L. u. LARKIN 1,885,608

NICAL REFRIGERATION MACHINES 2 Sheets-Sheet 1 gwumkoz Le5fer ll. Lark in Nov. 1, 1932. L. u. LARKIN 1,385,603

CONTROL DEVICE FOR MECHANICAL REFRIGERATION MACHINES Filed July 5. 1929 2 Sheets-Sheet 2 W /e t 18 l9 y gwwnto'o LE5? u. Larfcz'zz WJW; M

Patented Nov. 1 1932 UNITED STATES PATE NT OFFICE LESTER U. LARKIN, OF ATLANTA, GEORGIA, ASSIGNOR TO LARKIN-WARREN REFRIGERATING CORPORATION, OF ATLANTA, GEORGIA CONTROL DEVICE FOR MECHANICAL REFRIGERATION MACHINES Application filed July 3,

This invention relates to a float valve assembly particularly adapted to be used in connection with mechanical refrigeration particularly the valve mechanism on the inside of the boiler, it being the object to prevent the return of the raw liquid or refrigerant to the compressor thus causing the suction line and base of the compressor to frost, causing loss of efliciency.

The principal object is to provide means for cutting off the suction line running from the float chamber upon the liquid in the boiler expanding to a point beyond the original suction tube or oil line.

Heretofore, upon the compressor being started, the relief of the pressure on the boiler or evaporator would allow the liquid to expand above the original suction line sucking raw liquid instead of gas. This causes a frosting of the suction line and the base of the compressor with a resulting loss of efliciency.

Another object is to provide means whereby oil will be obtained from the quietest 2:;-

point in the boiler, so that it will have minimum of liquid in it. Prior to my invention, it was customary to extend the oil pipe only a short distance from the liquid line Due to the violent circulation obtained in my coil, I found it was necessary to extend this pipe a substantial distance from the liquid line valve, as it is highly essential to prevent any of the liquid mixing with the Another object is to provide a valve that even when slightly corroded will function. With the usual type of valve used which merely serves to cut off the liquid line, before the liquid can exert suflicient pressure to fication and claims.

Referring to the drawings:

Figure 1 is a diagrammatic view of the entire apparatus;

Figure 2 is a fragmentary perspective of the valve assembly from the inside;

- wall of the boiler.

1929. Serial No. 375,869.

Figure 3 is a section taken on line 3-3 of Figure 1;

Figure 4 is a section taken on line 1-4 of Figure 8; and

Figure 5 is a section taken on line 5-5 of Figure 4.

In the drawings; in which like parts are designated by similar numerals:

Numeral 1 refers to a boiler having an auxiliary suction line valve 2 with a float valve assembly 3. An oil return pipe 4 and a liquid supply line 5 are secured on a mounting ring 6. A compressor 7 and motor 8 are shown in the diagrammatic View. A float ball 9 is connected by an arm 10; the arm 10 being pivotally connected to a supporting structure 11, which in turn is secured to the mounting ring 6.

Extending from the arm 10 is a stop member 12 designed to contact with the under surface 13 of the supporting structure 11. Extending up from the arm 10 is a lever 14 to which is connected a needle valve 15 designed to close the liquid supply line 5. Adjustably secured to the arm 10 is a second arm 16, which in turn is connected at 17 to a needle valve 18. The needle valve 18 is designed to control the oil return pipe 4. An adjustable screw 19 secures the arm 16 to the arm 10. Extending from the oil return pipe 4 is a long pipe 20, preferably of copper, which is designed to return the oil to the compressor 7 and maintain a given level. The pipe 20 extends much further than the usual oil return pipe and is adjacent the far A bafile plate 21 extends from opposite the return gas tubes 22 to approximately an inch below the downturned end of the oil return pipe The gas tubes 22 are tubes extending from the coils (not shown) for discharging the refrigerant which will be in gaseous form into the float chamber.

As actually operated, upon the start of the compressor, the liquid in the boiler will expand due to the relief of pressure, and result in a rise in liquid level. Since the float ball 9 has reached its highest point previous to this time, the liquid will be forced over the float ball 9, and where the suction line is placed in its usual position, without any valve controlling the same, the liquid will be forced into the suction pipe, causing the same to frost and oftentimes reach the compressor, likewise causing frosting of it with resulting loss of efficiency.

In my invention, since the float 9 has reached its uppermost limit, the liquid supply line 5 and the oil return pipe 4 will be closed by reason of needle valves 15 and 18. Since these two pipes are closed regardless of how much the liquid may expand, or how high the level may become in the boiler, no liquid can enter the oil return line I. The valves 15 and 18 will remain closed until the auxiliary suction pipe 2 has drawn oif suflicient gas to lower the liquid level., Upon the liquid level being reduced, the float ball '9 will be lowered accordingly, and in turn, causing the valves 15 and 18 to open, admitting liquid through the pipe line 5 and returning oil through the oil return pipe 4. The pipe E20 is designed to contact with the oil which is always present on the surface of the liquid and return the same to the compressor 7 for lubricating purposes.

Should the level of the liquid fall so low so that the pipe 20 is out of contact with the oil, gas will be drawn to the compressor 7 in the same manner as the auxiliary pipe 2 will return gas to the compressor 7. The baflie plate 21, which is placed opposite the gas return tubes 22 causes the semi-gas and liquid to be forced downwardly below the oil level. This prevents the return semi-gas and liquid from returning directly on top of the oil and mixing with it, and also prevents interference with the drawing off of the oil by the pipe 20 which would result if the semigas and liquid were allowed to return immediately on top of the oil.

It is obvious that there may be variations in structure and design from the disclosures made here, and I do not intend to limit myself to the particular means shown herein, but claim any corresponding structure which may come within the scope of my invention.

I claim:

1. In a boiler of a refrigerating machine having a liquid inlet conduit and float con trolled valve in said conduit, an oil suction conduit opening into the boiler, a valve in said oil suction conduit and means connecting said last mentioned valve with the float controlled valve whereby said valves will be operated in unison or predetermined sequence as desired.

2. In a refrigerant boiler, an inlet conduit for a refrigerating liquid, an outlet conduit for oil and an outlet conduit for gas, means for closing said outlet conduit for oil upon the liquid refrigerant in the boiler reaching a predetermined position.

3. In a refrigerant boiler, including inlet and outlet conduits for a refrigerant, an outlet conduit for oil, means for closing said inlet and oil conduits upon the liquid refrigerant in the boiler reaching a predetermined position.

4. In a refrigerant boiler, a liquid inlet and oil outlet, a valve in said oil outlet and means operated by the liquid refrigerant level in the boiler to close said valve at a predetermined level of the refrigerant.

5. In a refrigerant boiler, a liquid inlet and oil outlet, a float member mounted in said boiler and operated by the refrigerant, means carried by said float member for closing said liquid inlet and oil outlet upon the float in said boiler reaching a predetermined position.

6. In a refrigerant boiler, a liquid inlet and oil outlet, a float member mounted in said boiler and operated by a liquid refrigerant therein, means carried by said float member for closing said oil outlet upon the fioat in said boiler reaching a predetermined position.

7. In a refrigerated boiler, a liquid inlet and gas outlet, an oil suction outlet emanating from the said side of the boiler that contains the liquid inlet, a valve for closing said oil outlet, a float for controlling said valve, an oil conduit extending from said oil suction outlet to a point adjacent the opposite wall, refrigerant circulating tubes connecting into the boiler, a baffle plate between the gas return ends of said tubes and said oil return conduit and extending below the free end of said oil conduit.

In testimony whereof I aifix my signature.

LESTER U. LARKIN. 

